Straight chain aldehydes

The basis of the high normal to isoaldehyde selectivity obtained ia the LP Oxo reaction is thought to be the anti-Markovnikov addition of olefin to HRhCOL2 to give the linear alkyl, Rh(CO)L2CH2CH2CH2CH2, the precursor of straight-chain aldehyde. Anti-Markovnikov addition is preferred ia this... 

The hydroformylation reaction is carried out in the Hquid phase using a metal carbonyl catalyst such as HCo(CO)4 (36), HCo(CO)2[P( -C4H2)] (37), or HRh(CO)2[P(CgH3)2]2 (38,39). The phosphine-substituted rhodium compound is the catalyst of choice for new commercial plants that can operate at 353—383 K and 0.7—2 MPa (7—20 atm) (39). The differences among the catalysts are found in their intrinsic activity, their selectivity to straight-chain product, their abiHty to isomerize the olefin feedstock and hydrogenate the product aldehyde to alcohol, and the ease with which they are separated from the reaction medium (36). 

Carboxylation/Oxidation of Straight-Chain 1-Olefins. Selective carboxylation of a-olefins to predominately straight-chain aldehydes is realized through specific catalyst systems and by careful control of reaction conditions. The aldehyde produced is then air-oxidized to the acid using a Mn catalyst. Heptanoic acid [111-14-8] and pelargonic acid [112-05-0] are produced commercially in this manner. 

Most of the straight-chain aliphatic aldehydes react with sulfur tetrafluoride in the usual manner to give the expected 1,1-difluoroalkanes as the only isolable products, reasonable yields are obtained in a narrow temperature range, from -20 to 40 C. An exception is butyraldehyde, which, when treated with sulfur tetrafluoride below 0 C, gives, in addition to 1,1-difluorobutane, considerable amounts of bis(l -fluorobutyl) ether [169] (equation 81)... 

Both straight-chain and branched aliphatic aldehydes show molecular ion peaks up to a minimum of Cl4 aldehydes. 

With most reducing agents, reduction of carboxylic acids generally gives the primary alcohol (19-34) and the isolation of aldehydes is not feasible. However, simple straight-chain carboxylic acids have been reduced to aldehydesby treatment with Li in MeNH2 or NH3 followed by hydrolysis of the resulting imine, ... 

The most influential parameter in cobalt-catalyzed hydroformylation was found to be carbon monoxide partial pressure. Piacenti et al. (30) showed this to be influential for both a- and internal olefins. Results are detailed in Tables V and VI. The percent of n-aldehyde rose rapidly as the carbon monoxide partial pressure was increased up to 30-40 atm CO further increase had little effect. 1-Pentene clearly gave a higher percentage of straight-chain aldehyde than 2-pentene, but the difference was insignificant in the lower Pco experiments. 

P(OC6Hs)3 (g) Reaction time (min) % Aldehyde which is straight-chain... 

The Fischer-Tropsch synthesis, which may be broadly defined as the reductive polymerization of carbon monoxide, can be schematically represented as shown in Eq. (1). The CHO products in Eq. (1) are any organic molecules containing carbon, hydrogen, and oxygen which are stable under the reaction conditions employed in the synthesis. With most heterogeneous catalysts the primary products of the reaction are straight-chain alkanes, while the secondary products include branched-chain hydrocarbons, alkenes, alcohols, aldehydes, and carboxylic acids. The distribution of the various products depends on both the type of catalyst and the reaction conditions employed (4). 

A reducing sugar has a sufficient amount of the straight-chain form present in equilibrium with its cyclic form such that the sugar will reduce Cu2+(aq) to insoluble, red Cu20(s). Only free aldehyde groups are able to reduce the copper(II) ion down to copper (I). 

Third, some of the pheromone components are simple and cheap compounds such as straight-chain esters and aldehydes, that are readily available in bulk. Others fall into a middle ground, whereby multigram-scale synthesis to produce sufficient material for use as trap lures should be possible. However, the pheromone structures of a number of species appear to be of sufficient complexity that it is unlikely that they could be made in sufficient quantity and at affordable cost for widespread use in pheromone-based control programs. 

A cluster of straight chain aldehydes and methyl ketones was identified from airborne volatiles collected from females of Hoplia equina. While all compounds were perceived by the males antennae, only tetradecane-2-one proved to be... 

The cationic rhodium catalysts with bisphosphine-modified CD-s were highly active in the biphasic hydroformylation of 1-octene (Scheme 10.8) [9,11]. In a two-phase system of l-octene/30 % DMF in water, quantitative conversion was obtained with 0.03 mol % of the catalyst at 80 °C and 100 bar syngas within 18 h (TOP = 180 h" ). Selectivity to aldehydes was higher than 99 % with 76 % regioselectivity in favour of the straight-chain product. 

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